Problem: $ \left(\dfrac{1}{81}\right)^{-\frac{1}{4}}$
Solution: $= 81^{\frac{1}{4}}$ Figure out what goes in the blank: $\Big(? \Big)^{4}=81$ Figure out what goes in the blank: $\Big({3}\Big)^{4}=81$ So $\left(\dfrac{1}{81}\right)^{-\frac{1}{4}}=81^{\frac{1}{4}}=3$